Testing for SARS-COV-2
Vitality is now offering SARS-CoV-2 antibody testing. Our test is an easy-to-do finger stick or blood test that is performed at Vitality Medical Wellness Center in Nashville. Results are available within 48-72 hours after the laboratory receives the specimen (overnight shipping is included in the cost of the test).
Many people have questioned the validity of the tests, so I have written a short blog to help you understand more about SAR-CoV-2 testing.
Testing for SARS-COV-2
One of the steps to understanding the spread and infectivity of SARS-CoV-2 is to do testing on our population. The United States has lagged in doing this, but now we have tests available to help determine who has or who has had the SARS CoV-2 virus, the virus that causes the COVID-19 illness.
What are the different tests available?
At this time, I am recommending 2 tests for people, the RT-PCR test and the blood antibody test. There are a lot of tests out there, and many are without validation, but these two tests have been studied the most and seem to be the most reliable (if done by a credible laboratory).
So, what’s the difference?
RT-PCR (reverse transcriptase-polymerase chain reaction) involves using a nasal swab directed to the back of your nose to detect active SARS-CoV-2 virus. It takes fragments of the virus and then replicates them. If you get a positive test result, then you are likely currently infected with the virus. However, this test is not without limitations. If you swab an area of the nose that is free of the virus, or if the virus has already moved from the nose to the lungs, then this test can come back negative, but in reality, you are actually infected with the virus. Therefore, a negative RT-PCR test does not necessarily mean that you do not have SARS-Co-V-2.
Serum antibody testing looks for antibodies (IgM, IgG) to the SARS-CoV-2 virus in your blood. Antibodies are part of your immune system that are produced when your body is exposed to a foreign invader. If your body’s mucus membranes (lining of your nose, lungs, gastrointestinal system) comes into contact with the virus, you will make IgA antibodies. As the infection moves deeper into the body, you will first produce IgM antibodies for two to five days before you start making IgG antibodies.
Should I be tested for SARS-CoV-2?
If you think you have an early active infection (fever, body aches, chills, cough, shortness of breath), you should have the RT-PCR test. If you think you may have already been infected or are in the later stages of the illness, then you should have the blood antibody test. Combining the blood antibody test with the RT-PCR may give the best results for detecting the infection if you are having symptoms. If you feel like you are getting over the infection or if you think you may have had the infection, to get the best results, I recommend doing the antibody test at least 14 days after your symptoms started.
If I have positive IgG antibodies, does it mean I am “immune”?
For many infections, the presence of IgG antibodies means that you are immune to the infection, or that you cannot get it again. SARS-CoV-2 behaves differently than a lot of other viruses, so we cannot say for sure at the time of this writing that positive IgG antibodies mean you are immune. From season to season, viruses tend to change or mutate, and this is what causes a problem creating immunity to a certain virus. Just because we are immune to one strain doesn’t mean we are immune to another.
If you have more questions regarding testing or are interesting in having an antibody test, please call Vitality at (615) 891-7500.